yeah drill out the welds, i drilled then diegrinded as i could only drill so big

then you need a hydrulic ram that fits inside the axle tubes to press them out, need to be able to handle about 20 tonne

then once they are out you cut how ever much off

then getting them back in is also fun, need a big press and i mean BIG, have to press one tube in at a time and it took about 16 tonne of pressure to get mine in all the way
also my press was only just big enough to fit the diff in as the platform will only go down so far
once they are in weld up the holes where it was originally welded....and your done

not the most fun job in the world when you do it the first time, and if you give up half way i dont think any diff shop will want to finish it

most engineering places should be able to shorten axles, or just ask the closest diff shop who they take their axles to